I suspect hate of SMGs is the way people articulate something more complex, which is annoyance at a combination of the way the maps encourage multiple encounters at SMG-optimal range, the way SMGs + Stock + Lightweight messed up the hitboxes (recent nerf to SMG stocks has helped) and the ubiquity of the PDW/MSMC.
You can try and get into an organised and methodical combat flow like in BO1, but in this game there are so many people charging around recklessly in confined spaces that you're liable to get killed at any moment anyway. Some people get annoyed and shout OP (same as with the R870) but this is just frustration at the dumbed down clusterf*** that is BO2. It's hard to believe how much treyarch somehow regressed since their last game, even though they dealt with the 2 game-wrecking perks.
I still believe the PDW is a problem. Its large 50 round magazine is just way to high and encourages spray and pray. The amount of times I've been killed after making it behind cover or rounded a corner because a guy simply did not stop shooting is a joke. Never before has a COD gun been so forgiving off inaccurate shooting.
When you add in its steady rate of fire, low manageable recoil, quick ADS, strafe and running speed and its tight hipfire spread then there's almost no drawback to using it. Sure you'll be beat at longer ranges but how many maps really have those long lines of sight? Most of the maps that do are the unpopular ones that never come up.
I don't believe its the best gun in the game or even the best SMG but being unlocked from the start it's the first gun most people use and they become too reliant on the large mag and when they try other guns they notice they're running out of ammo faster and just go back to the PDW. That's why its the most used gun in the game and you see tons of guys with like 3k PDW kills and barely a handful with anything else.
Call me a crybaby if you must, I don't feel I'm wrong in pointing out that this gun is the root of the laser sight, hip fire , spray 'n' pray nature of this game.
TL;DR 50 round magazine for an SMG is too damn high.
I rarely even see laser sights on PDW, or most SMGs. Its primarily silencers.
If spray n pray is your reason do you think LMGs are a problem?
Long lines of sight? Cargo, Yemen, Drone, Mirage, Downhill, Hydro, Standoff, Overflow, Slums, Carrier
Maps you could argue not so much good long lines of sight - Hijacked, Plaza, Express, Grind, Nuketown. But Id say if you stick to outside on Plaza, Grind & Express you'll be just fine.
LMGs would require Lightweight, Stock, Quickdraw and Laser Sight to be remotely close to the PDW in run'n'gun. Sure they're great at holding down a specific part of the map but nearly all game modes require you to chase some kind of objective and be on the move. Even doing it on a gamemode like Domination is risky because of constant spawn flips and other players headless chicken approach your likely to be shot from anywhere at anytime.
Whether you agree with me or not, when the most widely used weapon in a CoD game isn't the one that is statistically the best then something doesn't add up. I've accepted that the maps, perks and gamemodes cater to an SMG run'n'gun dominated game but that doesn't mean I can't complain about it.